Recently, in the field of micro-processing in the production of semiconductor devices and liquid crystal devices, fine patterning has rapidly been developed with the progress of lithography technique. In a technique for fine patterning, irradiation light having a shorter wavelength used. Specifically, ultraviolet ray typified by g-ray (wavelength: 438 nm) or i-ray (wavelength: 365 nm) used as conventional irradiation light has been replaced by DUV (Deep Ultra Violet).
At present, a KrF excimer laser (wavelength: 248 nm) lithography technique is introduced in the market and a trial of introducing an ArF excimer laser (wavelength: 193 nm) lithography technique, which is intended to realize shorter wavelength, has been made. Furthermore, a F2 excimer laser (wavelength: 157 nm) lithography technique has been studied as a next generation technique. As a lithography technique, which is slightly different from these techniques, an electron beam lithography technique and a EUV lithography technique has intensively been studied.
As a high resolution resist to irradiation light having a short wavelength or electron beam, a “chemically amplified photoresist” containing a photo acid generator is proposed and the chemically amplified photoresist are intensively improved and developed at present. In a chemically amplified positive resist, a dissolution rate to an alkali developing solution of a polymer for resist must be increased by an action of an acid and a polymer having a structure, in which hydrophilic groups are protected with acid-eliminating protective groups, is widely used. As a resist for ArF excimer laser lithography, patent document 1 discloses a polymer having, as a constituent unit, a monomer in which meth)acrylic acid is protected with an acid-eliminating protective group. Patent document 2 discloses a polymer containing a constituent unit represented by the following formula (5).
in the general formula (5), R represents a hydrogen atom, a methyl group, a linear or branched hydroxyalkyl group having 1 to 4 carbon atoms, or a linear or branched fluorinated alkyl group having 1 to 4 carbon atoms; R3 each independently represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms, and at least one of R3(s) represents the alicyclic hydrocarbon group or a derivative thereof, or any two R3(s) are combined with each other together with carbon atoms attached thereto to form a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, and the remaining R3 represents a linear or branched alkyl group having 1 to 4 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof; and U represents a divalent bridged hydrocarbon group having 5 to 12 carbon atoms.
However, in the case of preparing the (meth)acrylate for forming an acid-eliminating constituent unit represented by the general formula (5) described in patent document 2, the esterification reaction between (meth)acrylic acid having a bridged hydrocarbon group combined with a carboxyl group (structure U in the general formula (5)) and a tertiary alcohol (C(R3)3OH) must be conducted. In this case, in order to increase reactivity of the esterification reaction, the esterification reaction must be conducted after forming an acid anhydride of (meth)acrylic acid having a bridged hydrocarbon group combined with a carboxyl group, or reacting the (meth)acrylic acid having a bridged hydrocarbon group combined with a carboxyl group with thionyl chloride to form an acid chloride, and there was a problem such as a lot of reaction steps are required.    Patent document 1: Japanese Unexamined Patent Application, First Publication No. 2003-122007    Patent document 2: Japanese Unexamined Patent Application, First Publication No. 2003-330192